Rapture3D Game is a utility that can enhance audio in your games and apps. Rapture3D has different versions that you can download from its website. The "Game version" is the one that ships with games that are supported by the app. It comes with an OpenAL driver, which can talk to games and Windows to redirect sound to your speakers. Only some games can be used with this app, and most of them ship with it.
The installation and configuration are rather easy, especially if you already have the audio working on your computer. After following a short installation wizard, you will be able to access the Rapture3D Speaker Layout utility. From here, you can change your speaker layout. There are quite a few different layouts available, including the most popular ones like Stereo, Surround 5.1, Surround 3D 7.1, and Surround 7.1. There is a test feature at the bottom of the screen that lets you play a sound through any of your speakers. This is great for when you want to calibrate your speakers.
After configuring your layout and playing with some of the other available settings, you can head into a supported game and this is where you will experience what Rapture3D can do. The inner workings of the app are complex, but, basically, what the app does is interpret the instructions of the game regarding what sounds to play on which speakers for the best possible sound.